First phase of infrastructure estimated at $5.8 million

NORTH LIBERTY– Mayor Pro Tempore Gerry Kuhl wants people to know; the city is addressing infrastructure needs in anticipation of the coming high school.
Council members were given progress updates for sewer, water and roads projects on the city’s eastern edge at their May 27 meeting. John Gade, project leader from Fox Engineering, reminded the council an overall sanitary sewer study was done in 2011. The expectation then was for growth to the city’s east, even prior to the Iowa City Community School District (ICCSD) decision to build a new 1,500-capacity high school at the intersection of Dubuque Street and North Liberty Road.
The goals were to get water and sewer to new school site, and open up the rest of about 1,000 acres of land for more development by extending public utilities. It will take about 3.3 miles of water main and 2.3 miles of sanitary sewer to do so.
Gade walked the council through the considered routes for new water and sanitary sewer mains to the east, land the City of North Liberty has annexed into city limits. Terrain plays a big factor in how public utilities are constructed, as well as projected development and the eventual use of the systems.
“When we designed the pump station, it was difficult because you are going to have a very low amount of initial flow until development progresses,” Gade explained. “So we sized it so we can change pumps through multiple stages of development. Because of that (initial low flow), we are also very concerned about odor. So we are going ahead and planning an odor control system.”
Also factoring into the projects is the proximity to Coralville’s northward-expanding city limits; the ICCSD plans to build a new 500-capacity elementary school across Dubuque Street and further east (expected to open fall 2019), likely spurring further residential development for Coralville in the area as well. Therefore, the construction projects offered some interesting possibilities for sharing the infrastructure.
“It turns out (Coralville has) 300 acres of development they are also trying to service. A good portion of our alignment is the same as where they are putting their sanitary sewer. So we’ve had conversations with Coralville, and instead of installing two lines, we are looking at the option of upsizing our sanitary sewer line, at a cost of about $430,000, to service this 300 acres.” If that occurs, North Liberty’s facilities would be collecting all the sewage from the Scanlon Farm property, including land belonging to Coralville. In return, explained City Administrator Ryan Heiar,
North Liberty’s west side has an area of similar size– about 400 acres– that currently contains a lift station.
“(Coralville) would bring their line up to connect with ours, we could eliminate the lift station, and then all of that sewage would flow to Coralville. So we’d basically be trading,” said Heiar.
Heiar said there were still many details to work out regarding the potential to share water and sewer systems with Coralville, but he would continue to pursue an agreement.
“Unless there are many objections, we’ll keep working toward that. We’ve checked with different cities, and there are a number of sharing (arrangements) out there, but nothing quite like this,” Heiar said.
Council member Coleen Chipman offered a few words of caution.
“There are different rates of development, and if we really develop quickly, they would be subsidizing us, and no city should subsidize another,” Chipman said. “We want to make sure we have equal amounts we are working with.”
Another potential sharing arrangement would come at the water main, Gade continued.
“Our concern was, we want to make sure we have enough gallons per minute (GPM) of fire flow, especially to the high school,” Gade said, referring to water pressure required to respond to structure fires. North Liberty has the potential to provide about 2,000 GPM, Gade said, but Coralville is also running water to the area. “We looked at options of connecting the two systems together. Coralville was going to install a booster pump to increase the pressure of the water main; they could delay that or potentially eliminate it by this connection.”
It would give both communities increased reliability, with two sources of water and an emergency backup, if a disaster should happen.
“That is advantageous even from a DNR (Department of Natural Resources) permitting standpoint,” Gade noted.
Gade said the estimated cost for the water and sewer projects are $5.8 million; about $1.33 million for water, $4.5 million for sewer. That estimate does not take into account any potential sharing opportunities with Coralville.
The final design for the water main and sewer lines is expected to be completed this month, with the goal of getting the project to bid this winter and construction to begin in the spring of 2015.
“With no rain delays, I would estimate it is about a year-long project,” Gade added.
“So we’ll be well in line with the opening of the high school and everything that has to proceed it,” Kuhl said. “I hope people will know we are on top of the sewer, water and roads, and that we will be asking our developmental partners to share in the costs of redevelopment of this whole area.”